"Zero Dark Thirty" begins in our mind's eye — our memories of 9/11 play out as a black screen is backed by the sounds of news reports, 911 emergency calls and tearful dying messages left on voice mails.

The movie about the long hunt for Osama bin Laden will have plenty to show us. But "Hurt Locker" writer Mark Boal and director Kathryn Bigelow want us to provide the rationale for the next 21/2 hours. What they're about to depict is the spy's-eye-view of this epic search — the tedium of false leads, and the torture.

Not sure what "waterboarding" is and why it was used? In an excruciating series of sessions in assorted CIA "black sites," an agent (Jason Clarke) punches, deprives of sleep and supervises the simulated drowning that gained infamy when the world learned that the beacon of democracy was using it on prisoners.

"When you lie to me," the agent purrs, "I hurt you."

The film spends its first 45 minutes showing that unnamed agent's efforts on a defiant al-Qaida prisoner (Reda Kateb of "A Prophet") while newcomer Maya (Jessica Chastain) sits in, observes, learns and strategizes.

The only judgment the film passes on this Bush-Cheney-era method is that it eventually got that crucial one kernel of information — the name of a courier to Bin Laden — that torture became more effective as a threat once it had been stopped, and the inference that this desperate "enhanced interrogation" might have slowed down the search.

"Zero Dark Thirty" reveals the price of the years of failure — attacks in Saudi Arabia, London, Pakistan, Afghanistan, on CIA agents themselves. And unlike your typical Hollywood thriller, there was nothing neat and quick about this hunt, or about the raid that Navy SEAL Team Six carried out at its culmination.

Two competing trails are pursued, one advocated by Maya, the other by an agent played by Jennifer Ehle. There's a rivalry, promising ideas are put forward, shot down.

Boal breaks the story up into episodes, key clues or sequences in the search identified by inter-titles — "The Meeting." "Tradecraft." The script forces patience on us, reminds us that there are no Hollywood shortcuts in the real world of discovering, chasing and identifying "targets."

Few American characters are identified by name, from the shoe-leather team doing the work to the SEAL Team and the end of the line. "Zero Dark Thirty" — the title refers to the military description of a half hour past midnight, when the actual Bin Laden raid took place — relies on what we remember about those years, the stakes, the details that emerged when it was all over.

And that raid? Bigelow plays it out in real time. No quick cutting, no magical Hollywood gadgets that make blowing open doors "Mission: Impossible"-easy. Things go wrong, and deaths, when they come, are brutal.

The film is a fascinating reconstruction of history. But aside from those aural opening credits, it's surprisingly unmoving, a clinical exercise that mimics the professionalism of those involved. Tempers flare, but only rarely. Mark Strong ("Sherlock Holmes"), as a mid-level CIA officer in charge of the task force, has his pound the-table-moment in front of the team: "We are FAILING. Get me TARGETS."

And Maya, the strain of the years of work having ended her patience for — well, patience — has a few blowups over the lack of urgency her bosses seem to have for acting on her big lead.

Breakdowns over losing friends and colleagues are muted. Chastain, like the woman she is playing, and Bigelow keep emotions in check.

We remember how it began and we know how it ends. So despite the obvious expertise in the filmmaking and the detail in the story, there's not much suspense, either. The genius of "Zero Dark Thirty" is that we feel exactly what those involved must have felt at the end. Not elation. Not the thrill of victory. Just relief.